Question

Why is inhalation an active process whereas exhalation is a passive process?

A) Inhalation involves the diaphragm contracting.
B) Exhalation requires muscle contractions.
C) Inhalation is driven by external forces.
D) Both inhalation and exhalation are passive processes.

Answer 1

Step-by-step explanation:

Inhalation is an active process because it involves the contraction of the diaphragm. The diaphragm is a dome-shaped muscle located beneath the lungs, and when it contracts, it flattens and moves downward. This action increases the volume of the chest cavity, creating a negative pressure that allows air to be drawn into the lungs.

On the other hand, exhalation is a passive process because it does not require active muscle contractions. During normal exhalation, the diaphragm and other respiratory muscles relax, and the elasticity of the lungs and chest wall allows them to return to their original positions. As a result, the volume of the chest cavity decreases, causing the air in the lungs to be expelled.

Therefore, option B (Exhalation requires muscle contractions) is incorrect, and the correct answer is option A (Inhalation involves the diaphragm contracting) as it accurately explains why inhalation is an active process and exhalation is a passive process.

Answer 2

Inhalation is an active process because it involves the contraction of the diaphragm, causing a lower air pressure that allows air to flow into the lungs. Exhalation is typically a passive process due to the natural elasticity of the lungs, allowing them to return to their resting state and expel air without muscle contraction, apart from during forced exhalation.The correct option is A.

Step-by-step explanation:

Inhalation is an active process because it involves the contraction of the diaphragm, which is a large, dome-shaped muscle. When the diaphragm contracts, it lowers and the thoracic cavity expands, causing a decrease in air pressure inside the lungs, thus allowing air to flow in. External intercostal muscles may also contract, further aiding in expanding the ribcage.

In contrast, exhalation is typically a passive process, where the diaphragm relaxes, and the muscles used during inhalation are released, allowing the lungs to return to their rest state due to their natural elasticity. This causes an increase in air pressure inside the lungs compared to the outside atmosphere, and air is expelled. However, during forced exhalation, such as during heavy breathing or coughing, muscles like the internal intercostals and abdominal muscles contract to actively push air out.

The differences in muscle activity during these processes explain why inhalation is considered active and exhalation passive. The process is driven by changes in pressures, and no external forces are involved, contrasting options A and C, and since option D states both processes are passive, which is inaccurate, the correct answer would be A: Inhalation involves the diaphragm contracting.